


A Hands On Experience

by skerb



Category: Undertale (Video Game)
Genre: Alternate Universe - Undertail (Undertale), Begging, Blindfolds, Couch Sex, Cunnilingus, Established Relationship, Fluff and Smut, Frottage, Kissing, Lemon, Light Bondage, M/M, Massage, Multiple hands, Oral Sex, Orgasm Delay/Denial, Sensation Play, Sensory Deprivation, Teasing, Vaginal Sex, magic used for bullshit sex reasons, sansby - Freeform
Language: English
Status: Completed
Published: 2019-09-05
Updated: 2019-09-05
Packaged: 2020-10-10 16:36:57
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,000
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20531141
Author URL: https://archiveofourown.org/users/skerb/pseuds/skerb
Summary: What starts off as a massage for Grillby turns into a display of every loving gesture Sans can think of. It's a good thing he's got a hand for every one.





	A Hands On Experience

Grillby was just leaving.

“no, c’mon. don’t be that way!” Laughter accompanied Sans’ voice, but Grillby was intent on leaving.

He had a long day, customers had been unruly and loud, and every part of him ached. He had his back turned to the jokester, hand at the ready to turn the door knob and escape.

Why had he even come here? Likely, it was due to the fact that he could never say ‘no’ to Sans.

_ “…Just tired,” _ Grillby muttered crisply. He heard a shuffle from behind him, then felt skeletal hands push around his waist and wrap around him in an embrace.

Sans’ voice buried into his collar next, “y’know i was just teasing. why not take a moment to relax? let’s go cabin-side. get a nice fireplace going...”

The fire monster’s shoulders tensed with the suggestion. 

“now what’d i say?”

Grillby knew he was only irritable from a long work day and he let his fingers slip from the door knob. Thoughtfully, he cupped the bony hands resting on his stomach. 

_ “Not much for entertaining the thought of being watched by a stranger while being intimate,” _ he muttered with a short sigh. It wasn’t the first time he had to remind Sans of a fire’s tendency to gossip, nor did he feel like it’d be the last.

Then Sans chuckled. It tickled the flames of Grillby’s neck, rising in volume by a fraction as though something had _ just _ occurred to Sans.

“i guess that’s one way to relax…” There was a sultry lilt to Sans’ voice and Grillby’s flames hiked up in rebuke. “nah. maybe something a bit more subdued. maybe a massage?”

Grillby turned his head to regard him. That permanent grin was still affixed to Sans’ mouth, though it was a little different than before. Almost as though he was hiding something. 

Sans was always up to something, one way or another. 

Grillby turned in the skeleton’s hold, a sigh passing between them as he hung his arms around Sans’ shoulders. Sans’ grin tugged a little more with a soft hum, knowing that he’d won favour with the suggestion.

“lemme show you something neat,” he murmured, his hands grasping at the fire monster’s sleeves. His body swayed into the movement, but he allowed Grillby to decide their direction. For a moment they remained as they were, bodies close, drinking in each other’s company. “i got a new invention to test out, if you wanna give it a go?”

Grillby hummed in consideration and leaned forward, relishing in the calm aura the lab gave off. It had a quiet sterile hum, a contrast to the mess strewn around the tiled floor. Gently, he pressed his mouth against Sans’ forehead in a kiss, watching as Sans’ eyes drifted closed and a delightful flush bloom on his face.

_ “…Knew there was likely something more to this visit. Who would have thought it would’ve turned out to be a booty call?” _ He couldn’t help the tease. It’d been enough to catch Sans off guard and his grin broadened daringly.

“well that’s not fair,” Sans muttered good-naturedly. “my intentions are pure.”

_ “Highly unlikely. At any rate, what is to be set fire today?” _

Sans looked almost giddy. “altablack.” With Grillby’s curious head tilt, he grinned a little more. “a little something from the lab me and alph have been working on. reinforced carbon atoms spliced with synthed rotdrium, helix compound twist, and…” he paused for emphasis, “a twenty-one-hundred kelvin melting point.”

Grillby scoffed, knowing that Sans was likely pulling his chain for comedic effect. While the other elements were unknown to him, he had in the past irreversibly rendered Sans’ last ‘test element’ into a hopeless mass of charred matter. One of which had scorched through the lab’s tiles just in front of Sans’ desk.

“interested?” There was a challenging note to the skeleton’s voice and a sparkle in his eye, daring him to back down. On the other hand, Grillby couldn’t help but smirk, all too aware of what the outcome would be.

_ “…Suppose I could entertain your pyromania for another day.” _

A triumphant smirk tugging at Sans’ teeth, he thumped the sides of Grillby’s chest as though to reassure him of his decision. The fire monster let out a gusty breath, led to the worn chaise lounge couch on the other side. It wasn’t fancy; it was mostly utilitarian, ugly and grey, and likely something Sans had gotten in the past because it would be good for his posture if he needed a quick rest. It’d been at his brother’s request, so he couldn’t argue.

It would serve them well, all things considered. Grillby was pulled onto it, patiently watching as Sans then turned and went to the cabinet across the room.

“it’s supposed to be, anyway,” Sans said as Grillby leaned back on the chaise, pressing his back against the cool wall for support. He heated it up effortlessly, but took care not to scorch the walls. “fireproof, i mean.”

_ “Sounds interesting, to say the least.” _

The door of the full-sized cupboard blocked the view of Sans’ body, so Grillby was unable to see his reaction. All he saw was the fact that the skeleton had concealed something in the palm of his hand and kept it hidden when he turned back towards him.

“you don’t sound convinced at all, man.”

Grillby rolled a shoulder a little nonchalantly. _ “Could very well be your operative term. I just don’t believe there is such a thing.” _

Sans’ grin tugged again but Grillby didn’t budge when the skeleton approached. “you’re just saying that `cause you’re proud,” he said, as though he was just baiting Grillby into an argument. It was such a shame the fire monster was only complicit in engaging like this when he was tired.

_ “A full-blown narcissist, then,” _ Grillby agreed placidly, unbothered by the way Sans continued to conceal whatever he held in his hands. _ “Call me old-fashioned for saying so, but anything can and will burn at the proper temperature.” _

Sans finally closed in and slung his arms around Grillby’s neck, his body between his legs. His teeth set against Grillby’s brow in an echo of affection, his fingers tickling the flames that lingered at the fire monster’s neck. It soothed an unspoken tension in Grillby’s back, making him relax just a little.

As though Sans felt it, he moved his hands in slow circles around Grillby’s shoulders, rubbing in deft, long strokes. He must’ve hid whatever it was up his sleeve or in his inventory, Grillby idly thought.

“i know, babe,” he said softly, depositing another kiss to the side of Grillby’s fiery temple. The fire monster hummed as his irritation was gradually soothed away, breathing in a soft sigh to exhale against Sans’ neck. “you’re all worn out… gotta take it easy. gotta chill-”

Grillby’s relaxed stance tightened a little with that, and Sans laughed at his poor choice in words.

“my bad, sorry. let off some steam…?” When Grillby sighed again, allowing himself to lean into Sans’ touch, the skeleton pressed another kiss to his forehead, his hands steady and beautifully rhythmic. Uncontrolled, Grillby let out a soft groan of appreciation. “you want me to keep going?”

Quietly, the fire monster nodded against him, pressing himself close to Sans so he could better reach. He was rewarded with the flex of Sans’ fingers, pushing against the knots of magic that had started to form just under his fires, aching to be rubbed free. Grillby made another soft noise, his flames curling as Sans’ fingers gradually eased away the tension.

His own hands stayed idle by Sans’ legs as Grillby hunched forward, his body moving with the earnest way Sans worked him over, down his neck, the little bit of pressure unlocking gustier breaths.

Unable to help himself, Grillby hummed low, nodding again with all relaxed yearning when Sans asked him, soft and as warm as he, “wanna lie down?”

Sans helped him from his jacket and his vest, carefully untying the furl of fabric at his throat. Grillby was content to hand the reins to Sans as his boots were unlaced and removed next, then his sleeve garters and the top few buttons of his chemise.

It was tender. It was sweet. Grillby appreciated everything Sans did for him, wanting nothing more than to hold him in his arms and to apologise for being short with him. Instead, Sans leaned over him, urging him to turn and lay down on his stomach. There was ample room on the chaise, though one of Grillby’s legs hitched up automatically to get more comfortable.

Situating himself on Grillby’s rear, Sans leaned down with his body weight into his hands and pushed against the ridges of firm flames and magma, condensed into a space that mimicked his own body type. Instead of arguing with himself on what they were called, Sans rolled his palms into Grillby’s shoulder blades, feeling and hearing the fire monster release a hiss.

But it wasn’t of pain. Grillby felt blissed out with the simple pressure, though a little awkward. When Sans let up, he inhaled slowly and removed his glasses, passing them back to the skeleton for safe keeping. Then he folded his arms under his face for a makeshift pillow, settling down with a soft exhale.

“comfy?” Sans enquired, his voice low and soft.

Grillby took another calming breath, his eyes fluttering when Sans passed his hand down the curve of his back.

_ “Keep going..?” _

“you got it, boss.” Grillby could practically hear the unrestrained delight in Sans’ voice.

He gave in to a small shudder, allowing himself to sink against the firm plush of the cushion as Sans pushed down again, closer to the middle of his back. He didn’t utter a noise, but his flames curled languidly, rushing to the area so that they could feel Sans’ touch. As a result, the area quickly became hot and Grillby could feel the jostle of Sans’ quiet chuckles.

He knew. Sans was always observant.

Grillby closed his eyes with the roll of Sans’ knuckles, hard bone kneading up his back from under his shoulder blades to his nape, melting all the knots from his body. He couldn’t help the appreciative moan when his body both relaxed and tensed, Sans’ hands roving in curled motions, slow and careful, ironing out his fatigue until Grillby melted into putty.

That simple pleasure hit the spot, eliciting an embarrassing little sound when it felt like Sans braced himself on one forearm and pushed with his dominant hand. It travelled down, firmly pressing, gliding down to roam the dip in his back. Grillby curled the toes on one foot as Sans’ fingers grazed by his side, seemingly innocent but igniting a private wish for more. He didn’t know if it was because he was warmer due to the relaxed state that he was in, but Grillby thought that Sans’ hands felt just a little absent of heat.

Not cold, just… not warm.

He huffed when he felt Sans’ teeth meet with his shoulder, a soft kiss placed there as bony hands pushed down again, thumbing a ridge that was particularly hard. Grillby couldn’t help but groan again with the pressure, now curling against the touch so Sans’ fingers dug in. It felt good. It felt _ really _ good, more pleasurable than he would’ve liked to admit.

“you like this?” Sans murmured, his voice a low whisper in the lab like a filthy secret. Grillby kindled a little brighter at that and buried his face, as redundant as it was to try and hide his pale flames. “it’s ok, grillby. i’ve got you. it’s alright to get riled up.”

Grillby’s laugh was sudden, having been caught off guard. He cracked an eye open and turned his head, only to have one of Sans’ hands cover what limited vision he had without his glasses. Oddly enough, the rocking pressure continued without a beat, eliciting heated shivers up his back. Sans was _ very _ good with his hands.

_ “More experiments…?” _ Grillby asked softly, his voice blissed out and content. He relaxed his body again, flames fanning out as he did so. _ “Feels good.” _

“that’s good, hun. you deserve it after a long day,” Sans said, his voice still soft.

Carefully, as though asking permission, Grillby felt a hand press down against the side of his hip. It wasn’t with as much pressure as the massage, but there was something urging in it, untethered and hungry. It made his temperature spike just a little and Grillby swallowed with the silent invitation. The hip press was like an enquiry.

_ Do you want more? _

They’d arranged it as such. If he didn’t outwardly say no, it was alright for Sans to explore. Their earlier days had been met with many explorations, but it never stopped Sans from appreciating his body from time to time, as infrequently as it’d become lately. Grillby missed the lingering touches, the caresses that made his flames whip about, abashed and excited. It was a treat.

He nodded against his forearm and drew in a sharper breath with Sans’ triumphant chuckle, feeling his bony hand move over his hip to push down underneath him. Grillby felt the throb echo in the emptiness between his legs but Sans didn’t touch him there, only drew his attention to his mouth when Sans gave his neck another kiss.

He nearly protested when the hand moved away, though it pressed against his abdomen and up the curve of his hip, eliciting him to raise himself for easier access. The hand didn’t return, only palmed at his side again, as though to savour the shape of his body.

The moment passed, Grillby sunk against the cushion with a deep sigh, closing his eyes behind Sans’ hand. He decided to only allow Sans whatever he wanted to do, whether it be teasing him with the mere _ thought _of intimacy, or just indulging in the gentle moment they found themselves in.

Regardless, Grillby settled, lowering his hips, only to have them eased up again with Sans’ free hand. He breathed in deeply when the skeletal hand grazed between his shirt and waistband, igniting the spot with such longing that Grillby had to restrain the huff he felt in his throat.

“you’re all pent up,” Sans said, an idle observation. Grillby’s core surged hotly with the way his voice heaved when Sans leaned more pressure into his back. “you really need to let loose more often, grillbz.”

Grillby’s sigh hitched when Sans eased up, his reach still under his chemise, venturing up his side. The flames under his clothes shuddered with anticipation, lingering long enough to curl against the intruding fingers as though to welcome Sans to more.

Sans leaned down over the fire monster, a contented little hum reverberating against Grillby’s back, appreciative and low, “you’re getting warm.”

Breathless and caught a little off guard with the comment, Grillby laughed. _ “Should hope so. Otherwise I’d have cause for worry.” _

Sans scoffed and Grillby could feel the hand roam higher, inching up towards his chest. Invitingly, he leaned onto his left side so Sans’ hand could move unburdened. The tips of Sans’ fingers flexed into the semi-permeable state of his body, barely touching the core of him, drawing another huff from Grillby. Then, again, the hand would retreat, leaving his fires stoked and craving.

Sans shifted above him, resting his forearm across his shoulder blades and running it down, the pressure sensually warm and steady. Grillby flexed his fingers against the chaise cushion, resisting the urge to look over his shoulder to see just what the skeleton was up to. With every pass, Grillby felt himself both relax and fire up a little more, just resisting the urge to outright groan with every touch Sans treated him to.

But he failed. With Sans’ next manoeuvre, Grillby groaned low in his throat, the sound pushed out of him, tight with want. He felt Sans stiffen above him for a fraction of a second and he turned his head, yearning to see the skeleton’s expression.

But again, Sans covered his eyes, not like it would help with how blind Grillby was without his glasses. His fire snapped in rebuke but he settled down anyway, feeling a slinky material flutter over the flames of his head, thin fabric that also felt soft and hummed with earthen magic.

He couldn’t see it well, but it was black, and most definitely held in Sans’ hand. Which was odd, considering that Grillby swore that he felt something inch just past his waistband again. Distracted by that, he inched his leg up, bent at the knee as the unmistakable feel of Sans’ magic followed the line of his hip and down again.

_ “Altablack?” _ Grillby murmured distractedly, attempting to ignore the way his body flared even more with Sans’ lingering touches.

“yeah, just a little strip of it. kinda wanna get you all hot and bothered to see how much heat it can withstand. thing is… i wanna see if you can hold out for me. test its limits, y’know?”

Grillby could practically feel the longing in Sans’ voice, sultry and smooth as the skeletal hand delved lower, tracing its fingers against his abdomen. He growled lowly, not one to be teased, his temperature rising above the careful warmth he assumed was safe for most. For Sans.

_“Ah-” _

Sans’ hand continued below, tracing aching circles slower, lower, coaxing Grillby to grind against him. Grillby heard Sans’ voice clear in his head, whispered next to his face like a secret.

“i wanna see how wrecked i can make you… and have you take it out on this little black cloth, ok?” To make his point, Sans delved his hand further, rubbing his fingers in a lazy circle closer to between Grillby’s thighs. He trembled with anticipation. “that alright with you?”

_ “Hnn… yes.” _

Grillby gusted a hot breath against the chaise cushion, singeing it in the process. He flushed, his flames peaking higher as he raised his hips again, silently begging for more. When Sans pulled away, Grillby made an almost scandalised sound, turning to look at him.

Blackness covered his vision and he froze for a moment, his flames flicking with pent up agitation. Grillby then swallowed, not used to the utter darkness that surrounded him. Delicately, he pulled his arm up, stunned at the way his flames couldn’t even branch out and tell him what was going on, to project a mirror of the world around him into his mind so he could see.

But it was gone, his body suspended in nothingness, with only Sans and the couch under him to ground him.

_ “C.. cannot see-” _ he gasped breathlessly, like a world without light held no oxygen to feed him either.

But there was Sans on his back, stroking his shoulders as he pulled the fabric away from Grillby’s eyes. The world suddenly bloomed with light and Grillby gasped in relief, only just noticing that he’d been trembling the entire time.

“you ok?” Sans asked, clearly concerned.

It took a moment for everything to buzz to the surface, touch and sound and fire bursting to life. Grillby turned his body a little and with it, the hand on his abdomen withdrew and the skeleton moved off his back.

“grillby?”

_ “Fine,” _ Grillby answered finally, gusting out a long and hot breath. _ “Had… merely startled me.” _

He wasn’t sure if the pause meant something else or if Sans was calculating something. But no, he appeared at least somewhat concerned, carefully bringing him up to hold in his arms.

Sans cradled his face with one hand, thumbing Grillby’s cheek as he nuzzled him close. “changed your mind?”

The fire monster felt a bloom of affection, tender like a bruise against his soul. He grinned to himself, relieved that his fright had subsided enough to squint in Sans’ general direction. All that the skeleton looked to be was a mottled grey-white blurr with a haze of blue. Pretty, but not what he was used to.

_ “I am fine,” _ he replied, though he had to think about it for a moment. _ “…Are you using magic?” _

Something in front of him moved, as though tauntingly. Grillby envisioned the image of jazz hands and suppressed a grin. Then Sans replied a little giddily, “o’course! otherwise things might get too hot to handle.”

A smirk pulled at Grillby’s mouth and he leaned forward to kiss Sans, missing his mouth but kissing close to his nasal aperture with a quiet laugh. Sans snickered and guided Grillby’s face with his hands, cupping each side as he kissed him, slow and sweet. With that, the fire monster shuddered, desire rekindling when a hand settled atop of his thigh, the thumb just barely stroking there.

It was so different to hand everything over to Sans, sight and touch and sound an intoxicating melange that Grillby had never felt before. He didn’t feel any of his previous possessivity, the desire to dominate or to overwhelm Sans. Sans just held him, gently, kissing him in a way that made his body and soul ache, that made him yearn to be touched more.

His mind focused on Sans’ tongue, gently testing his willingness, Sans’ thumb still tracing aching circles close to his inner thigh. Grillby sighed against his mouth, rolling his hips toward Sans’ touch with silent permission.

One of Sans’ arms slinked down, carefully plucking another button free on his chemise, then the next. Grillby’s mind tugged at the way there appeared to be more points of contact than what Sans should’ve been able to do, but he was blissfully distracted when Sans’ other hand again delved down between his waistband and stomach.

He groaned into Sans’ mouth, pushing against him as he felt Sans’ grin quirk through their kiss. Grillby allowed his magic to gather, intent to form something for Sans to touch, when the skeleton moved back.

Gasping breathlessly with his temperature on a steady incline, Grillby tried to focus on the skeleton in front of him, attempting to parse what exactly was going on. He pushed forward to kiss again, grabbing Sans’ hand that seamlessly took his own, fingers lacing together.

“patience.” Grillby loved the way Sans chided him despite how out of breath he sounded, too.

So he couldn’t help but grin between increasingly frequent kisses, hot and deep. _ “Your trait,” _ he paused to hungrily steal another, _ “not mine.” _

Sans laughed quietly, a devious little sound as his hands led Grillby’s arms, pushing forward.

It wrung a shudder from him when Sans carefully eased him down, rolling Grillby onto his back. Sans straddled his thighs, pushing the hand in Grillby’s grasp next to his shoulder, and bent down to capture another kiss.

There was another tug that Sans definitely couldn’t have reached with his left hand to where it now groped at Grillby’s side. The fire monster huffed against another deep kiss, his hips moving to garner more friction. Sans groaned as he rolled his hips forward, his hand going deeper, teasing and secretive until Grillby’s breaths quickened.

“hold out for me?” Sans whispered, making Grillby shudder again with the suggestive, authoritative tone. Grillby forced his magic to retreat with a little difficulty. As though in reward, Sans’ hand pushed lower, resuming the small circles that made Grillby’s legs start to tremble again. Like he was silently suggesting for Grillby’s magic to form something else entirely. “i’ll make it good for you…”

Grillby couldn’t resist that voice. Not when Sans sounded as debauched as he felt. Grillby lifted his hips to grind into the skeleton’s fingers and against the body above him, testing the hold on his hand. It was strong, as though all of Sans’ weight was put into it at once and then some. He felt a little untethered for the bold display of strength, making Grillby yearn for more.

“there you go, baby,” Sans continued, his voice low and hot between them. Grillby reopened his eyes to find the startling darkness had returned, but he was no longer afraid. He was too focused on the sultry heat of Sans’ voice, his eagerness to touch him and the distracting way the skeleton’s fingers danced over his stomach. “you lemme know if you’re uncomfortable, ok?”

Hastily, Grillby nodded, his throat feeling tight. He inhaled with the next movement, a sharp pleasure building as Sans skimmed his touch up his shirt to feel small jerks. Grillby’s mouth hung open, his eyes searching under the blindfold, idly wondering if that was Sans’ hand or his magic.

He honestly couldn’t tell.

The hand tested the edge of his body, fingertips idly tracing the curves of his collar to down his chest, digging in to breach his core. It felt good and Grillby tensed with a tight little noise, a surge of pleasure making his flames hike up with excitement. He couldn’t see what Sans was up to, didn’t know where he’d venture next. His breath stuttered when Grillby next had to more consciously prevent his magic from forming, his fire wild and excited.

A bloom of pleasure flooded him when Grillby felt Sans’ tongue test the heat of his chest, just aching movements away from touching his soul. He keened softly, needing to reach out and grasp at Sans’ back, to pull him closer so he could feel more.

But he was tethered to the spot. Each of Sans’ hands grasping his own, lacing their fingers together to hold him where he wanted him. There was a grip further down around Grillby’s wrists, arresting him from seeking out Sans’ shoulders, to pull him close like he wanted to. Grillby knew it was impossible, but dare he think some sort of ghostly tentacles were holding him down…?

They were too thin, too dextrous. His face burned a little more when he tested the strength of them, bony phalanges tightening just a fraction before easing their grip. His soul started to beat quickly, excited for what that meant. He could feel Sans’ tongue delve between the crags in his chest, tantalisingly close to his soul that it startled a sharp gasp from him, Grillby’s voice crackling urgently. His body heaved into Sans’ touch, just as the skeleton pulled away.

Grillby couldn’t help the thin noise that escaped him, the bubbling flare of desire that coursed through Grillby’s body when Sans leaned down, his tongue finding the soft curve of his soul. It was brief, but for that blinding instant Grillby was riding the edge of bliss, legs hiking up, wanting to encircle his lover and pull him close.

Noises fell from his mouth with increasing fervour as Grillby craned his head, feeling the fierce blaze scald around his body like a building storm. He groaned, the sound filthy and loud as pleasure broiled within him, heightening, just _ aching _ to be set free-

Again, Sans stopped. Grillby released a steamy huff, his body slackening from being wound up so much, but his hands trembled, still in Sans’ hold, his legs shaky at the knees.

Something was holding his ankles, too. Something that matched the tensile strength on his wrists, holding him with just enough pressure to keep him down. It sent another flare of heat to kindling Grillby’s flames, sparking them in brilliant rich hues of velvety soft ambers, corals and golds. He heard Sans sigh, all want and appreciation, then he whispered as Grillby felt a pair of fingers slide around the fabric of his belt loops, tugging just enough to tease.

“what do you need, hm?” Sans murmured, sending a thrill through Grillby’s body as his thumbs braced against the jut of his hips, kneading into the shape of his body. It wasn’t anywhere close to where Grillby wanted to be touched, but he huffed out an excited breath anyway. “you must be pretty wound up by now, huh…? nowhere to go… just heating up, more and more… turning such a pretty shade of rosy just for me-”

Grillby huffed again, more insistently, as though his impatience could be conveyed through that alone. He could practically hear the grin in Sans’ voice, and the skeleton lowered his volume just a hair.

“you comfy, hun? y’want me to hold you down like this? to mark you up `til you’re all pretty and breathless and can’t take it anymore?”

Grillby’s throat felt tight with the words, making more heat scald across his face. Somewhere at the back of his mind, he wasn’t sure if the Altablack fabric would be able to withstand it. All he knew was that he didn’t care, Sans’ suggestions igniting a deep-seated need within him to, yes, make him his, just how he’d always wanted.

_ “Filthy talk,” _ he managed, his voice a little hoarse, though Grillby let out a breathless chuckle despite himself. He was rewarded with hands moving to unbutton the front of his slacks, no expense spared, as impossibly, another hand passed behind the fly. He groaned, restraining himself as the pads of the fingertips traced idle circles, making him bite the corner of his mouth, twisting in Sans’ grip as pleasure broiled to the surface. _ “Mm-!!” _

“it’s barely dirty talk, grillby,” Sans observed, that hint of mischievousness touching this voice. Grillby felt his breath against his stomach when Sans exhaled, as though preparing himself to savour something he’d always coveted. “though i’m a bit hungry for something else.”

Those words hit Grillby like a punch and he inhaled a slow and shaky breath, the anticipation surging all the way down to his core. There were far too many points of contact, too many to count nor focus on: around his wrists, his arms, palming at his thighs, his sides, gently caressing his face. He shuddered when Sans (or whatever this happened to be) slid the waistband of his trousers past his hips, lifting his lower half so his slacks could be fully removed. A shudder passed through his flames, the absence of clothing leaving him feeling exposed.

He’d opted thus far to hold on for Sans, who had asked him so sweetly. He would’ve held on longer, but Sans was cruelly skillful with his mouth. He felt the skeleton’s hands grasp his rear, pulling him up and across Sans’ lap, kissing down Grillby’s abdomen with such deliberation that the fire monster couldn’t help but jerk every time he felt Sans kiss him. The blindfold afforded him no luxury to watch, instead leaving him surprised and anticipating every touch like he was starving for it all.

He tested the strength of his restraints again, his soul thundering when he was gently pushed back. Distractedly, Grillby felt Sans’ mouth follow the natural line of his hip and down between his legs, making him want to bend a leg at the knee to brace himself. It took everything within him not to summon something on the spot; for him to leave it bare as always until Sans asked what he wanted of him.

Grillby groaned again, echoing an unrestrained, satisfied sound that Sans made, laving his tongue over the spot where something, _ anything, _ could be. Grillby shuddered, the spot tingling, aching and silently begging to be more.

_ Hold on for me. _

He wasn’t sure if he could. Grillby clasped the hands, holding them as heat surged within him again, coaxing his magic to form. He resisted, if just barely, when Sans gave the spot another deft lick, firmly pressing his thumbs inward as though he was outlining where Grillby’s pussy would be. Then Sans enclosed his mouth around the area and sucked. The flames retreated, the throbbing heat beating like a pulse until Grillby threw his head back, mouth wide with a cracked groan, sudden and _ loud. _

His body arched, chest heaving short gasps as Sans’ tongue worked against him, enticing his frustrated magic to form. Sans’ tongue flicked in perfect little circles, varied in pressure, duration and eagerness. The air crackled around him and Grillby understood, vaguely, Sans’ idea to rile him up. His legs twitched when he finally couldn’t hold out any longer, gritting his teeth when an urging push against his pubis caused his magic to fall out and form a ready willing pussy.

Of course Sans moved away. Grillby sunk back against the cushion, his legs parted around Sans’ head, his desperate breaths short and hot. He felt the drag of a thumb over the fabric of the blindfold, a tease that assured him that Sans was just within reach. Grillby felt a whimper, a bare plea stuck in his throat when he felt the pad of Sans’ thumb trace down below and part him.

“tell me what you need,” Sans murmured. When his voice was soft with that rough huskiness, affection and hunger rippled through Grillby’s body.

Grillby’s face burned, _ all of him _ burned for more, to be touched until he was satisfied.

But he was hopeless when it came to dirty talk. Grillby swallowed hard, a few meaningless, fiery sounds escaping him before he could properly articulate; _ “I… want you-” _

Despite the cop out, Grillby was rewarded with a slow circle against his clit, the flat of Sans’ thumb grazing over the sensitive spot in languid strokes. Grillby’s breaths hitched, focused on the familiar point of pleasure. It was something to cling to, until Sans paused, taking his hand away, much to Grillby’s protests. Then his thumb came back, resuming its tantalising, curving and firm strokes, much wetter and better than before.

Grillby hummed, gratefully pressing his hips into Sans’ hands, blindly turning to face him. There was a slow build, a quiet, unsatisfied hunger that the fire monster just couldn’t get enough of. He wasn’t used to such passivity, where he’d be the one to take what was willingly offered…

Yet Sans was teasing him. He supposed it was only fair, in a way, for all the times that he’d done the same to Sans before. But Grillby was never used to expressing what he wanted, their activities always devolving into an overly heated wrestling match, desperate to come apart in each other’s arms.

So he nodded shortly when Sans hummed, raising his hips again as though the skeleton was intent on eating him out. His soul stuttered, throbbing in tandem with his body’s heat that Grillby was sure he was burning _ something. _

Sans used the broad face of his tongue, from bottom to top, ending with a firm stroke of the tip of his tongue. He passed over the sensitive nub, lingering there to draw Grillby’s clit into his mouth to hear the fire monster’s fiery expletive. Grillby’s hips jerked and his back arched as he was teased, it never being enough, his magic kindling hotter, only to flare down between rests.

He ached. His throat felt hoarse. Grillby shuddered out a breath to calm down as his hips were lowered again, nestled in Sans’ lap.

“how you doin’?” Sans asked, his tone still low. “still with me?”

It took a few moments for Grillby to form a coherent thought. Hastily, he nodded, and a hand cupped one side of his face, tender and loving. He couldn’t help the small jolt that passed through his system when Sans’ hand traced a gentle circle to his inner thigh, stroking as though to soothe him.

_ “All… alright,” _ Grillby affirmed, half swallowing his words when Sans pulled him further into his lap. He felt the distinct absence of heat that accompanied Sans’ magic, hard and pressed against his thigh. _ “Please-” _

“please?” Sans repeated.

Grillby couldn’t tell if he was amused or not, but a sliver of desperation coiled inside of him with the skeleton’s voice. _ “Yes… please. I want you to-” _

A slick movement passed between his folds when Sans pulled him closer, dragging the head of his dick through the warm glide of Grillby’s pussy. There was a trembling that Grillby just couldn’t stop as he attempted to angle his hips to accommodate Sans, to ease him inside like he wanted. He bit the corner of his mouth, feeling a slight nudge and his legs spread further open by hands he couldn’t see, feeling too much like Sans’ magic to convince him that it was anything else.

The tip of Sans’ dick pushed up along his slit again, smearing the wetness of his cunt up to his clit, winding him up with the simple, slippery movements that Sans was angling himself at. Grillby’s throat was tight as he tried again, a frustrated noise forced out of him with the third and fourth pass.

Was it Sans’ idea to drive him mad? He groaned when Sans’ fingers flirted with his pussy, his right hand thumbing at his clit just before he thrusted against his folds, a deep and empty longing echoing inside of him. Grillby arched to get more of Sans, his mouth hanging open, dragging in desperate gasps as the skeleton teased him, taunting him with what he so craved.

_ “You… a-are… torturing me-” _ Grillby shuddered, his grip almost death-like against the hands in his. His hips jerked when Sans pulled him forward again, a low and filthy growl piercing their symphony of moans. It went through him like a shot, eliciting a tense shudder to ripple through Grillby’s flames. _ “F.. fuck, I--Sans, please-” _

It was enough. He felt the words affect Sans as soon as they’d left his mouth, travelling up the skeleton’s back to nestle into his soul, no doubt. The soles of Grillby’s feet were pushed down to the chaise’s cushion, legs comfortably bent as Sans pulled him down and onto his dick.

The spiralling pleasure and the sensory deprivation was enough for Grillby to clench down on Sans, to use him as a point of reference as to where he was in the world. Grillby made a desperate little noise as Sans stilled, to let him get used to the swell of him. It ached, stretching him wider than he’d ever known, or perhaps Grillby just felt that needy. He throbbed around Sans’ dick, attempting to catch his breath as Sans tested the angle. With a harsh gasp, the fire monster lifted his hips to accept more of him.

A few long strides had Grillby swearing softly, the glide slick from all the teasing and playing. His throat still felt tight, trapped on ragged gasps as Sans pushed into him with every thrust, his fingers grazing his clit.

“god, you’re so hot-” Sans groaned against him, breathless as his thrusts became unsatisfyingly shorter. It started to rub at Grillby inside, putting just enough pressure against his g-spot to be maddening when barely any movement at all was enough to get him going.

Grillby groaned, throat unlocked and loud as he pivoted his hips just so, Sans’ next thrust inside of him hitting the sweet spot. For a moment Grillby thought the breath had been knocked out of him, until he realised that Sans had reached up, carefully stroking the slight in his chest in time with his thrusts.

Sans kept them measured and small, rubbing at his inner walls so much that Grillby thought the idea was to inch him off the chaise instead of to fuck him. But it was a slow creep of pleasure, his heat scalding as it rose with intensity.

He could hear Sans’ gasps, his restrained little moans of appreciation when Grillby clenched him as though to force him to move, to slam into him harder. Sans’ breaths hissed, his hips’ movements stuttering, no doubt on the edge as Grillby tested the restraints again. An inferno engulfed the two of them when finally, _ finally, _ Grillby felt overwhelmed at long last.

He pushed against the hands that trapped him, now able to secure his grip on Sans’ hips to impatiently pull him forward, into him. Grillby growled when he realised that he could see that pretty grey and blue figure, and a slew of paler mottled blurs around Sans. Sans pushed him down with a breathy laugh, his true hand lacing their fingers together as his dominant hand went between them to secure Grillby’s left thigh, using it to aid their movements.

Grillby grabbed a fistful of Sans’ shirt with his free hand, relishing the feeling of Sans’ spine under his fingers and the tightness as tension flooded over his lover. Grillby pushed a heated kiss to the side of Sans’ neck as the skeleton whispered desperate profanities and praise into the space between them, his thrusts more frantic and hard. Grillby could feel the sweat on Sans’ bones against his flames as they excitedly surrounded them both, overwhelming the skeleton enough that the new angle he pushed into Grillby was enough to make his pussy flutter and clutch at him, rhythmically clenching around Sans as he came.

As Sans’ movements died down, Grillby pulled him close, just allowing them both to exist, floating around in euphoria until their brains resettled. The fire monster traced idle fingertips over the notches in Sans’ spine, a subtle tremour intermittently passing through Sans’ body with his affections.

His own body was shaky, wrung out from being so ruthlessly fucked. Grillby just hummed to himself, a smirk cracking his face when Sans allowed his full weight to sink against his body.

“welp. can’t say we didn’t try,” Sans croaked against the side of Grillby’s face. Blearily, Grillby eyed him; if he was exhausted after work, there was no way in hell that he was well rested then.

_ “Altablack… failure.” _ Grillby sighed, half fire and half sound, wrapping his arms around Sans so he’d be sure that he could touch Sans for as long as he liked. _ “Nine-hundred… Kelvin… maybe…” _

Sans sighed against him, the breath long and deep. “was afraid of that.”

_ “Aluminium… melting point…” _

“no need to be rude, man.”

Grillby smiled warmly, holding Sans so that he could feel his ribs expand against his chest every time Sans took in a breath. He savoured it, nodding against Sans’ head.

_ “Better luck… next time…” _

**Author's Note:**

> I started this early last year but the idea continued to haunt me so I got the thirst to finish it!! ✧*｡٩(ˊᗜˋ*)و✧*｡


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